The lead prosecutor who secured the conviction for the "Grid Kid Slayer" was not aware of her key witness' psychiatric records until several years later.

"I didn't have them in my possession at the time," said Assistant Brooklyn District Attorney Anna-Sigga Nicolazzi at the hearing to determine whether John Giuca's 2005 murder trial was prosecuted fairly.

Giuca's attorney, Mark Bederow, grilled the seasoned prosecutor Monday to show that their key witness, John Avitto, was not credible based on his history of fabricating stories to benefit himself, and his psychiatric records.

Avitto recanted his trial testimony eight years after it helped convict Giuca for the Oct. 12, 2003, murder of Fairfield University football player Mark Fisher on Argyle Road in Ditmas Park.